My 4 week old comfort feeds, it differs from proper feeding as he is only on for a couple of minutes, doesn't suck properly then falls asleep. As soon as I try to put him in his cot he wakes up and starts mouthing but he does the same all over again. I really don't want him to get into the habit of him going to sleep on the breast or on me. Health visitor has suggested leaving him to cry which I have tried. 20 minutes at the most so far but I really don't know how long to leave him crying?